Flexed sounding board



Nov. 19, 1929 MJR. HUTCHI'YSON 7 1,735,860

FLEXED SOUNDING'BOAR'D Filed April 1. 1927 2 Sheets-Sheet -1 INVENTOR.Miller Reese Hufchison ATTORNEY NOV. 19, 1929. M R HUTCHISQN 1,735,86@

FLEXED SOUNDING BOARD Filed April 1, 1927 2 Sheets-Sheet INVEN TOR.Miller iFeese HuTch/son BY Q $46M A TTORNEY Patented Nov. 19, 1929'chiral) ESTATES PATENT OFFICE HUTCHISON, OF WEST ORANGE, NEW JERSEY,ASSIGNOR, BY MESNB ASSIGNMENTS, TO ACOUSTIC PRODUCTS COMPANY, OF NEWYORK, N. Y., A 003- ronurron or DELAWARE FLEXED SOUNDING IBQARDApplication filed April 1,

This invention relates to the faithful reproduction of sound.

The invent' on has for its particular object the provision 'of-improvedmeans for producing simultaneously musical notes having a wide range offrequencies, together with all the upper harmonics necessary forimparting quality or timber to music whereby the sounds of difierentmusical character may be readily 1o identified. The. 'nvention hasparticular reference to a the reproduction of orchestral, band or chordmusic so that the sounds produced by the difierent instruments or voicesof an ensemble are emitted in the same relative intensities as in thecase of the original rendition of the music. i

Heretofore in the reproduction of such music by radio loud speakers andthe like great difliculty has been experienced in obtaining even anapproximation of bass notes.

It appearsthat this difiiculty is at least in part the result ofimpressing upon the ap ar-atus energy corresponding to the higherrequencies of the musical register, and that when the apparatus isresponding to such higher frequencies it does not faithfully respond tothe energy of low frequency. This difliculty is not apparent when theapparatus is reproducin the bass notes singly as in the case of a asssolo, but develops immediately when the bass notes are to be produced atthe same time as the notes of higher range.- Consequently it has beenfound with structures of the prior art that when proper response isobtained in the case of a bass sold, the response with an ensemble ofinstruments is not faithful and the bass notes are not properly balancedwith the higher notes, so that the music is not always reproduced withfidelity.. g

In attempting to secure the proper balance which is desirable I havediscovered that sounding elements" of wood operate well production oforchestral, band and choral music. In providing-such wooden elements,however, it is important to secure the proper relation between thedimensions of the element and to providemeans for flexing the under allthe conditions obtaining in the re- 1927. Serial Ira-180,181. 7

formed of wood and to the provision of differently flexed elements, eachhaving apredetermined configuration, in combination with means forimpressing thereon vibratory energy.

The energy impressing means comprises generally an electromagnetic unithaving an actuating element operatively connected to the respectivesounding element, and one feature of the invention relates to applyingthe unit to the sounding board at a point spaced from one edge of thesounding board by a predetermined amount, depending on the thickness andtexture of the wood.

Another feature relates to the provision of a plurality of difierentlyflexed sounding elements.

Other objects will appear from the following description taken inconnection with the accompanying drawings in which Fig. 1. is asectional elevation' of one embodiment of the invention in which thesounding elements are flexedlongitudinally taken on the line 11 of Fig.2;

D Fig. 2 is a horizontal section taken on the line 2-2 of Fig. 1;.

Fig. 3 is a side elevation of a modified form of the invention in whichthe sounding elements are flexed transversely;

Fig. 4 is a horizontal sectiontaken on the line H of Fig. 3;

Fig. 5 is a side elevation of a modified embodiment having foursoundings elements each flexed transversely; g

Fig. 6 is a horizontal section taken on the line 66 of Fig. 5; l

Fig. 7 is a side elevation of,a modified form of the invention havingfour sounding elements each of which are flexed longitudinally;

Fig. 8 is a horizontal section taken on the line 8-8 of Fig. 7;

Fig. 9 is a side elevation of another 'modi;

fication of the invention having four sounding elements two of which areflexed longitudinally and the other two transversely;

Fig. .10 is a horizontal section taken on the 'line 1010 of Fig. 9;

Fig. 11 is a side elevation of another modification of the invention inwhich two transversely flexed sounding-elements of unequal length arearranged at an acute angle with respect to each other;

Fig. 12 is a horizontal section taken on the line 1212 of Fig. 11.

Like reference characters denote like parts in the several figures ofthe drawing.

y In the following description and claims, parts, characteristicfeatures and functions will be identified by specific means forconvenience of expression, but they are intended to be as generic intheir application to similar parts or equivalent construction as the artwill permit.

Referring to Fig. 1 there is provided a base 20 supporting fourvertically extending ele ments 21, 22, 23, 24. Two of the elementsdesignated 21 and 22 respectively, are plain rectangular panels of woodprovided merely for the purpose of support. The other two elements 23,24 are formed ofcarefully-kiln dried wood having all sap carefullyremoved to avoid fracturing the fiber and having its grain extendingvertically. Each sounding element 23, 24: is flexed longitudinally.

.A top 30 is placed over the upper ed es of the elements 21, 22, 23, 24;and is provided on its lower face with a pair of depending brackets 31,32 each having secured thereto an electromagnetic unit 33, 34. of theloud speakertype for converting undulatory electricalenergy intomechanical movement. It isunderstood that the units 33,34 are con-'nected by conductors 35, 36 in circuit with a source of undulatoryenergysuch as a radio receiving set, a phonographic Pickup device, apublic address system or the like. The unit 33 actuates a link 37serving as an operative connection to the sounding element 23, and thelink 37 engages the respective sounding element at a point 38 which isapproximately fifteen per cent of the total length of the free portionof the sounding element 23 from one of its edges, the distance dependingupon the thickness and texture of the board. Similarly the unit 34.includes a link 39 forming an operative connection with the soundingelement 2 1 and is secured thereto at a point l0 which is alsoapproximately fifteen per centof the total length of the free portion ofthe respective sounding element 24:. The top 30 is apertured as at $1and the bottom is apertured as at 42 for the emission of sound wavesfrom the interior of the device.

In operation, undulatory electrical energy is transmitted overconductors 35, 36 to the units 33, 3 1 and causes longitudinal movementof the respective links 37 This movement is applied to the soundingelements 23, 24 causing them to vibrate accordingly. It is acharactertistic of a longitudinally flexed sounding element that itresponds especially well to low pitched notes. It is in' effect a seriesof long parallel wood fibers extending longitudinally and responding torelatively low natural frequencies. Furthermore, by applying thevibratory energy near one end of the structure the center portion isoscillated to a greater degree producing vibrations of relatively largeamplitude in the surrounding natural medium without excessive clearancebetween the armature and poles of the actuating unit. In the modifiedform of the .inventio shown in Figs. 3 and 4, four vertically extendingelements 51, 52, 53 and 54 are provided. The elements 51 and 52correspond to the plane rectangular panels of wood shown as at 21, 22ofFig. 2 and are provided merely for the purpose of support. The other twoelements 53, 54 are formed of carefully kiln dried Wood having its grainextending vertically with respect to Fig. 3 and flexed transversely. Anelectromagnetic unit 55 is provided for the vibratory element 53 beingsecured thereto by a link 56 engaging the sounding element at a pointwhich is approximately 15% of the total length of the free portion ofthe sounding element from one of its edges. A second electromagneticunit 57 having a link 58 is similarly connected to the 05 op aosedsounding element 54.

n the operation of the embodiment shown in Figs. 3 and 4 electricalenergy modulated in accordance with a signal current of complex waveform is applied to the units 55, 57

and causes longitudinal movement of the respective links 56, 58. Thismovement is communicated to the sounding elements 53, 54: causing themto vibrate accordingly; It is a characteristic of sounding elements ofthis 5 form to respond to notes of relatively higher pitch than those towhich the longitudinally flexed sounding elements of the embodiment ofFigs. 1 and 2 respond.

The embodiment of Figs. 5 and 6 is similar to that of Figs. 3 and 1:except that four transversely flexed sounding boards 61, (52, 63

and 64 are provided. Each sounding element Y is provided with anelectromagnetic unit such as 65 having a link 66 operatively connectedto the respective sounding element at a point which is approximately 15%of the total length of the free portion of the sounding elemenafronroneof its edges.

In operation electrical undulatory energy volume of sound emitted in alldirections with substantially equal intensity is thus obtained.

The embodiment of Figs. 7 and 8 is similar to that of Figs. 1 and 2except four longitudinally flexed sounding boards 71, 72, 7 3 and 74 areprovided. Each is formedas in the embodiment of Figs. 1 and 2 and isprovided with an electromagnetic unit such as 75 having a link 76.operatively connected to the respective sounding element at a pointwhich is approximately 15% of the total length of A Thus it will beseenthatIhave provided a.

sound propagator formed of a cellular material, flexed in varyingcombinations to produce music of improved quality. The cellular textureof the material, and the flexure of the material greatly improves thequality of the free portion of the respective sounding \the sound Byproviding sounding elements fixed in different planes brilliant as wellas I element from one of its edges.

In operation electrical undulatory energy mellow sounds are effectivelyproduced thus is applied to the four electromagnetic units increasingthe attractiveness of the music to a simultaneously and each causesvibration great extent. a

of the associated sounding element in accord- The invention upon whichthis application ance with the signal wave. A larger volume is based isbroader than the specific embodiof sound, of low pitch is thustransmitted ment shown and described for the purpose of effectively inall directions. illustrating at least one of the ways in which In themodified form of the invention it'may be employed. The scope of theinven-.

shown in Figs. 9 and 10 four vertically eX- tion is therefore to beunderstood as not betending elements 81, 82, 83 and 84 are proinglimited by the present specific descrip vided. The elements 81, 82 aresimilar in tion. I intend no limitations other than construction to thesounding elements 58, 54 those imposed by the claims.

of Figs. 3 and 4 and are flexed transversely. What is claimed is:

The other two elements 83, 84 are similar in construction to theelements 7 3, 74- and are rality of sounding boards flexed transversely,

flexed longitudinally. I other sounding boards flexed longitudinally,Each of the four sounding elements 81, 82, and means forvibrating all ofsaid boards 83 and84 is provided with an electromagnetic imultaneou ly.

unit such as 85 having a link 86 operatively 2. A sound propagatorcomprising a pluconnected to the respective sounding element ralit fdiff tly fl x d di b ard edges.

at a point which' is approximately 15% of forming a hollow chamber and acorrespondthe total length of the tree portion of the re ing pluralityof operating units for actuatspective sounding element from one of ltSing said boards respectively. x 3. A sound propagator comprising a plu-In operation electrical undulatory e rgy rality of sounding boardsflexed transverseis applied to the four electromagnetlc unlts ly, othersounding boards flexed longitudi- 1. A sound producer comprising a pluas simultaneously and each causes vibration nally, said boards formingcollectively a hol fectively in all directions.

of the associated sounding elementin accordlow chamber, and means foractuating said ance with the signal wave. A larger volume b -dg i lt lof sound, of low pitch is thus transmitted ef- York and State of NewYork, this 30th day of In the modified form of the inventlon M h A, D1927,

shown in Figs, 11 and 12 two elements 91, 92,

positioned at art acute angle with respect to one another. Each isprovided with an electromagnetic unit such as 93, 93, each unit having alink such as 94 extending therefrom to the respective sounding elementat a point which is approximately 15% of the total length of the freeportion of therespective sounding element from one of its edges. In thedrawing the sounding elements 91, 92 are shown as being flexedtransversely, but it is understood that they may be flexed longi;

tudinally asdiselosed in Figs. 7 and 8, or one may be flexedtransversely and the other flexed longitudinally as in the combinationshown in Figs. 9 and 10.

In the operation of the modified form of I the invention of Figsll and12 electrical undulatory energy is applied to the two electromagneticunits 93 simultaneously and each causes vibration of the associatedsounding element in accordance with the signal wave. Musical sound ofimproved quality is thus produced.

Signedat New York, in the county of New MILLER REESE HUTOHISON.

